Hundreds of people black and white, many holding hands, packed an Alabama church which was bombed by the white supremacist Ku Klux Klan 50 years ago to mark the anniversary of the blast that killed four little girls and became a landmark moment in the civil rights struggle.

Hundreds of people black and white, many holding hands, packed an Alabama church which was bombed by the white supremacist Ku Klux Klan 50 years ago to mark the anniversary of the blast that killed four little girls and became a landmark moment in the civil rights struggle.

The bombing became a powerful symbol of the depth of racial hatred in America's South and helped build momentum for later laws, including the 1964 Civil Rights Act and the Voting Rights Act of 1965.

The Rev Arthur Price taught the same Sunday school lesson that members of the 16th Street Baptist Church heard on the morning of the bombing, A Love That Forgives. Then the rusty church bell was tolled four times as the girls' names were read.

Bombing survivor Sarah Collins Rudolph, who lost her right eye and her sister Addie in the blast, stood by as members laid a wreath at the spot where the dynamite device was placed along an outside wall.

Ms Rudolph was 12 at the time and her family left the church after the bombing. She said it was important to return in memory of her sister, who was 14, and the three other girls who died - Carole Robertson and Cynthia Wesley Morris, both 14, and Denise McNair, 11. "God spared me to live and tell just what happened on that day," said Ms Rudolph, who gave evidence against the Klansmen convicted years later in the bombing.

Congregation members and visitors sang the old hymn Love Lifted Me and joined hands in prayer. The sombre Sunday school lesson was followed by a raucous, packed worship service with gospel music and worshippers waving their hands. During the sermon, the Rev Julius Scruggs of Huntsville, president of the National Baptist Convention USA, said, "God said you may murder four little girls, but you won't murder the dream of justice and liberty for all."

Later an afternoon commemoration included US attorney general Eric Holder, Alabama governor Robert Bentley, former United Nations ambassador Andrew Young, civil rights campaigners the Rev Jesse Jackson and the Rev Joseph Lowery, and director Spike Lee, who made a documentary about the bombing.

The church was full, with the only surviving mother of one of the girls, Maxine McNair, sitting in the front row.

Mr Holder called the girls' deaths "a seminal and tragic moment" in US history and recalled gains that followed their killings like the Civil Rights Act and the Voting Rights Act. Alluding to the supreme court decision this year that struck down a key part of the voting law, Mr Holder said the struggle continued decades later. "This is a fight that we will continue," he said.

The dynamite bomb went off outside the church on September 15 1963. Of the Klansmen convicted years later, one remains in prison. Two others who were convicted died in jail. Two young black men were shot dead in Birmingham in the chaos that followed the bombing.